如何设置Boost RTree坐标系？线段相交查询报错求助

为实现RTree的query功能以查询两段线段的相交情况，编写了如下代码：

using Point2d =
    boost::geometry::model::point<double, 2, boost::geometry::cs::cartesian>;
using Segment2d = boost::geometry::model::segment<Point2d>;
using SegmentRtree =
    boost::geometry::index::rtree<Segment2d, boost::geometry::index::rstar<16>>;

for (int point_index = 0;
     point_index + 1 < segment.line_segment().point_size();
     point_index++) {
    const Segment2d segment_in_range = {
        {segment.line_segment().point()[point_index].x(),
         segment.line_segment().point()[point_index].y()},
        {segment.line_segment().point()[point_index + 1].x(),
         segment.line_segment().point()[point_index + 1].y()}};
    uncrossable_segments_in_range.insert(segment_in_range);
}

编译时出现如下错误：

/home/xx/xx/xx/xx/xx/xx/xx/xx.cc:220:66:   required from here
/home/xx/xx/xx/build_x86/_deps/boost-src/include/boost/geometry/strategies/index/services.hpp:31:5: error: static assertion failed: Not implemented for this coordinate system.
   31 |     BOOST_GEOMETRY_STATIC_ASSERT_FALSE(
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

请问该如何设置Boost RTree的坐标系以解决此问题？

• 问题本质：Boost.Geometry的RTree核心基于几何体的**包围盒（Bounding Box）**构建索引，直接将Segment2d作为存储类型时，默认索引策略无法自动适配线段的包围盒计算逻辑，导致坐标系相关的断言错误。

• 最简修正方案：用std::pair包装线段与唯一标识（如ID），让RTree自动提取线段的包围盒作为索引键：

  // 修改RTree的存储类型为线段+标识的组合
  using SegmentRtree = boost::geometry::index::rtree<
      std::pair<Segment2d, int>, 
      boost::geometry::index::rstar<16>
  >;
  

  插入数据时同步调整：

  // 以point_index作为线段标识示例
  uncrossable_segments_in_range.insert(
      std::make_pair(segment_in_range, point_index)
  );
  

• 自定义索引策略方案：若不想用std::pair，可手动实现indexable函数，显式计算线段的包围盒：

  namespace bg = boost::geometry;
  namespace bgi = boost::geometry::index;
  
  struct SegmentIndexable {
      using result_type = bg::model::box<Point2d>;
      result_type operator()(const Segment2d& s) const {
          result_type box;
          bg::envelope(s, box); // 计算线段的包围盒
          return box;
      }
  };
  
  // 在RTree定义中指定自定义索引策略
  using SegmentRtree = bgi::rtree<
      Segment2d,
      bgi::rstar<16>,
      SegmentIndexable
  >;
  

内容的提问来源于stack exchange，提问作者wong